E9-3609. Airworthiness Directives; General Electric Company (GE) CF6-80C2B5F Turbofan Engines

AGENCY:

Federal Aviation Administration (FAA), Department of Transportation (DOT).

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

The FAA proposes to adopt a new airworthiness directive (AD) for GE CF6-80C2B5F turbofan engines. This proposed AD would require removing certain part number (P/N) high-pressure compressor rotor (HPCR) 11-14 spool/shafts before they exceed a new, reduced life limit. This proposed AD results from an internal GE audit that compared the life limited parts certification documentation to the airworthiness limitations section (ALS) of the instructions for continuing airworthiness (ICA). We are proposing this AD to prevent HPCR 11-14 spool/shaft fatigue cracks caused by exceeding the life limit, which could result in a possible uncontained failure of the HPCR spool/shaft and damage to the airplane.

DATES:

We must receive any comments on this proposed AD by April 21, 2009.

ADDRESSES:

Use one of the following addresses to comment on this proposed AD.

• Federal eRulemaking Portal: Go to http://www.regulations.gov and follow the instructions for sending your comments electronically.
• Mail: Docket Management Facility, U.S. Department of Transportation, 1200 New Jersey Avenue, SE., West Building Ground Floor, Room W12-140, Washington, DC 20590-0001.
• Hand Delivery: Deliver to Mail address above between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays.
• Fax: [phone].

FOR FURTHER INFORMATION CONTACT:

Robert Green, Aerospace Engineer, Engine Certification Office, FAA, Engine & Propeller Directorate, 12 New England Executive Part, Burlington, MA 01803; e-mail: [e-mail]; telephone [phone]; fax [phone].

SUPPLEMENTARY INFORMATION:

Comments Invited

We invite you to send us any written relevant data, views, or arguments regarding this proposal. Send your comments to an address listed under ADDRESSES. Include “Docket No. FAA-2009-0121; Directorate Identifier 2008-NE-36-AD” in the subject line of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of the proposed AD. We will consider all comments received by the closing date and may amend the proposed AD in light of those comments.

We will post all comments we receive, without change, to http://www.regulations.gov,, including any personal information you provide. We will also post a report summarizing each substantive verbal contact with FAA personnel concerning this proposed AD. Using the search function of the Web site, anyone can find and read the comments in any of our dockets, including, if provided, the name of the individual who sent the comment (or signed the comment on behalf of an association, business, labor union, etc.). You may review the DOT's complete Privacy Act Statement in the Federal Register published on April 11, 2000 (65 FR 19477-78).

Examining the AD Docket

You may examine the AD docket on the Internet at http://www.regulations.gov; or in person at the Docket Operations office between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The AD docket contains this proposed AD, the regulatory evaluation, any comments received, and other information. The street address for the Docket Operations office (telephone [phone]) is the same as the Mail address provided in the ADDRESSES section. Comments will be available in the AD docket shortly after receipt.

Discussion

The ALS in the ICA for CF6-80C2 series engines incorrectly cited a cyclic life of 20,000 cycles for the HPCR 11-14 spool/shaft, P/N 1703M74G03, installed in CF6-80C2B5F engines. The certified life for this spool/shaft in CF6-80C2B5F engines is 19,500 cycles. The HPCR 11-14 spool/shaft, P/N 1703M74G03, wasn't originally certified for CF6-80C2B5F engines, but was included in the ALS under the CF6-80C2B5F engine model listing with a 20,000 cycle limit. When the spool/shaft was certified for the CF6-80C2B5F, it was certified for 19,500 cycles. GE changed the ALS to 19,500 cycles. Exceeding the 19,500 cycle life limit could result in fatigue cracks starting and growing until the spool/shaft fails. This condition, if not corrected, could result in possible uncontained HPCR spool/shaft failure and damage to the airplane.

FAA's Determination and Requirements of the Proposed AD

We have evaluated all pertinent information and identified an unsafe condition that is likely to exist or develop on other products of this same type design. We are proposing this AD, which would require removing from service CF6-80C2B5F engines with HPCR 11-14 spool/shafts, P/N 1703M74G03, before they exceed 19,500 cycles.

Costs of Compliance

We estimate that this proposed AD would affect one engine installed on an airplane of U.S. registry. We also estimate that the proposed actions would require no work-hours per engine. No parts are required. Based on these figures, we estimate there is no cost of the proposed AD to U.S. operators.

Authority for This Rulemaking

Title 49 of the United States Code specifies the FAA's authority to issue rules on aviation safety. Subtitle I, Section 106, describes the authority of the FAA Administrator. Subtitle VII, Aviation Programs, describes in more detail the scope of the Agency's authority.

We are issuing this rulemaking under the authority described in subtitle VII, part A, subpart III, section 44701, “General requirements.” Under that section, Congress charges the FAA with promoting safe flight of civil aircraft in air commerce by prescribing regulations for practices, methods, and procedures the Administrator finds necessary for safety in air commerce. This regulation is within the scope of that authority because it addresses an unsafe condition that is likely to exist or develop on products identified in this rulemaking action.

Regulatory Findings

We have determined that this proposed AD would not have federalism implications under Executive Order 13132. This proposed AD would not have a substantial direct effect on the States, on the relationship between the national Government and the States, or on the distribution of power and responsibilities among the various levels of government.

For the reasons discussed above, I certify that the proposed AD:

1. Is not a “significant regulatory action” under Executive Order 12866;

2. Is not a “significant rule” under the DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and

3. Would not have a significant economic impact, positive or negative, on a substantial number of small entities under the criteria of the Regulatory Flexibility Act.

We prepared a regulatory evaluation of the estimated costs to comply with this proposed AD. You may get a copy of this summary at the address listed under ADDRESSES.

List of Subjects in 14 CFR Part 39

• Air transportation
• Aircraft
• Aviation safety
• Safety

The Proposed Amendment

Under the authority delegated to me by the Administrator, the Federal Aviation Administration proposes to amend 14 CFR part 39 as follows:

PART 39—AIRWORTHINESS DIRECTIVES

1. The authority citation for part 39 continues to read as follows:

Authority: 49 U.S.C. 106(g), 40113, 44701.

§ 39.13

[Amended]

2. The FAA amends § 39.13 by adding the following new airworthiness directive:

General Electric Company: Docket No. FAA-2009-0121; Directorate Identifier 2008-NE-36-AD.

Comments Due Date

(a) The Federal Aviation Administration (FAA) must receive comments on this airworthiness directive (AD) action by April 21, 2009.

Affected ADs

(b) None.

Applicability

(c) This AD applies to General Electric Company (GE) CF6-80C2B5F turbofan engines with a high-pressure compressor rotor (HPCR) 11-14 spool/shaft, part number (P/N) 1703M74G03, installed. These engines are installed on, but not limited to, Boeing 747 series airplanes.

Unsafe Condition

(d) This AD results from an internal GE audit that compared the life limited parts certification documentation to the airworthiness limitations section (ALS) of the instructions for continuing airworthiness (ICA). We are issuing this AD to prevent HPCR 11-14 spool/shaft fatigue cracks caused by exceeding the life limit, which could result in a possible uncontained failure of the HPCR spool/shaft and damage to the airplane.

Compliance

(e) You are responsible for having the actions required by this AD performed within the compliance times specified unless the actions have already been done.

New Reduced Life Limit for the HPCR 11-14 Spool/Shaft

(f) Remove any CF6-80C2B5F turbofan engine that has an HPCR 11-14 spool/shaft, P/N 1703M74G03, before the spool/shaft meets or exceeds the new, reduced life cycle limit of 19,500 cycles.

Installation Prohibition

(g) After the effective date of this AD, do not install any CF6-80C2B5F turbofan engine that has an HPCR 11-14 spool/shaft, P/N 1703M74G03, that meets or exceeds 19,500 cycles.

Alternative Methods of Compliance

(h) The Manager, Engine Certification Office, has the authority to approve alternative methods of compliance for this AD if requested using the procedures found in 14 CFR 39.19.

Special Flight Permits

(i) Under 14 CFR part 39.23, we are prohibiting special flight permits for this AD.

Related Information

(j) Contact Robert Green, Aerospace Engineer, Engine Certification Office, FAA, Engine & Propeller Directorate, 12 New England Executive Part, Burlington, MA 01803; e-mail: [e-mail]; telephone [phone]; fax [phone], for more information about this AD.

Issued in Burlington, Massachusetts, on February 12, 2009.

Francis A. Favara,

Manager, Engine and Propeller Directorate, Aircraft Certification Service.